A compound represented by the general formula:wherein Ring A is a C6-14 aryl group or the like, L is —NRLCO— or the like (wherein RL is a hydrogen atom or the like), Ring B is a C6-14 aryl group or the like, X is a C1-3 alkylene group or the like, Y is a C1-3 alkylene group or the like, Z is an oxygen atom or the like, R1 and R2 are each independently a hydrogen atom or the like, and R3, R4, R5 and R6 are independently a hydrogen atom, a halogen atom or the like, or a pharmaceutically acceptable salt thereof, or a solvate thereof, has an Aβ production inhibitory effect or a BACE1 inhibitory effect and is useful as a therapeutic agent for a neurodegenerative disease caused by Aβ and typified by Alzheimer-type dementia.
